How SARS Works

The Spread of SARS

Much like other respiratory illnesses, SARS seems to be spread by close contact. For example, a person infected with SARS could cough or sneeze, contaminating the immediately surrounding air with tiny droplets of infected matter. Someone in close proximity of the infected person could then breathe in air that has been contaminated. Because the cause of the SARS infection is yet unknown, scientists are considering other possibilities of communication. According to the CDC, "it is possible that SARS can also spread more broadly through the air or by touching an object that has been contaminated." A recent update on the WHO Web site addresses some other possibilities:

The SARS outbreak in Hong Kong SAR has developed an unusual pattern of transmission. This pattern is different from what is being seen in the vast majority of other SARS outbreaks, and is not yet fully understood. The number of cases is continuing to increase significantly, and there is evidence that the disease has spread beyond the initial focus in hospitals.
These developments raise questions related to other routes of transmission, in addition to well-documented face-to-face exposure to droplets released when an infected person coughs or sneezes. Epidemiologiests are considering whether SARS is being transmitted in Hong Kong by some environmental means for which no satisfactory explanation has been found.

To illustrate the communicability of SARS, consider this: According to the New York Times, as of March 29th, 249 individual cases of SARS could all be traced to one man. That's an incredible amount of people infected by one person. Of those infected, 214 were medical personnel or health-care workers.

Both the CDC and the WHO are working hard to reduce the spread of SARS by informing healthcare workers and the general public about the condition. Some of the recommendations for medical personnel in direct contact with SARS patients are:

SARS patients and the family members and healthcare workers in contact with them should take precautionary measures for at least 10 days after SARS symptoms have passed. The CDC and the WHO recommend recovering patients and people in contact with them:

Every species on Earth, from the majestic humpback whale to the bacteria happily living in your gut, has a special role to play within a defined ecosystem. Can organisms ever trade their existing niches for new ones?

Imagine a time in Earth's far-flung past when organisms didn't swim through the oceans or populate the lands. Even the mighty dinosaurs hadn't arisen. Will the planet ever return to that lifeless state?